The present invention relates to a vehicle which is equipped with a light-emitting apparatus at a lower part of its entrance. The present invention also relates to a lamp device for a vehicle such as a stop lamp, a tail lamp and a winker lamp, particularly relates to a lamp device for a vehicle in which a light transmitting tube is used as a light emitting portion.
A bus is conventionally equipped with a lamp for lighting up steps at the entrance thereof. A car is equipped with a lamp at the underside of the inside of a door thereof so that the lamp lights up the entrance of the car when the door opens.
It takes a lot of time to change the lamp when the lamp is down, because it is necessary to remove screws for a lamp cover.
A conventional lamp device for a vehicle has a lamp and a reflective board, and there is a space between the reflective board and a transparent board or a lens installed in front of the reflective board. The conventional lamp device for a vehicle has a large thickness because of the space. Furthermore, it is considerably expensive to manufacture a lamp device having a curved shape which imitates a curve of a car body.
As well known, a meter case installed in an instrument panel of a vehicle is equipped with a speedometer, a tachometer, an odometer, a water temperature gauge of a radiator, a winker lamp, and a lamp for lighting up the front of the meter case, etc. In order to improve visibility at night of indicators such as the speedometer, the meter case is provided with transparent parts made of slit or transparent synthetic resin which are formed in shapes corresponding to scales of the speedometer, numbers, and the like.
An electronic circuit unit is installed on the back of the meter case. The electronic circuit outputs driving signals to meters including the speedometer, the tachometer, and the like installed in the meter case, and also checks trouble or failure of the meters. The electronic circuit unit is integrally equipped with a support case consisting of a shield cover and the like, and the support case is fixed to the meter case with screws. The shield cover covers a circuit substrate which is mounted with electronic parts of the circuit unit in order to shield electromagnetic wave.
A flexible wire board for the meters is installed on the back of the meter case. The meters in the meter case are electrically connected with the electronic circuit unit by lead wires and connectors. Alight bulb for illumination with a socket which permits installation and removal of the bulb is installed on the flexible wire board and is electrically connected with the flexible wire board.
It takes a lot of time to change lamps installed on the back of the meter case when these lamps are down, because it is necessary to separate the electronic circuit unit completely from the meter case by removing screws which fix the electric circuit unit to the meter case and by removing connectors, too.
Japanese patent publication H9-282918A disclosed a back light system for a meter of a vehicle, which is equipped with a light transfer board, a fluorescent tube along the edge of the light-transfer board, a reflective sheet on the back of the light-transfer board, and a diffuser panel disposed on the front of the light-transfer board. The back light system does not need light bulbs on the back of the meter case. However, the lifetime of the fluorescent tube is relatively short, and it takes considerable time to change the fluorescent tube because it is necessary to remove the meter case from an instrument panel.
The first object of the present invention is to provide a vehicle having a light-emitting apparatus at the lower part of the entrance thereof, in which the light-emitting apparatus is low in weight and is excellent in durability, and furthermore, the light-emitting apparatus has a light source which can be repaired easily.
A vehicle of the present invention has a light-emitting apparatus at the underside of the entrance thereof. The light-emitting apparatus has a light transmitting tube which emits light from the circumferential surface, and a light source installed at one end of the light transmitting tube.
Light from the light source is introduced into the light transmitting tube and emitted from the circumferential surface of the light transmitting tube.
The light transmitting tube may be arranged at the underside of the entrance without a cover, so as to make the light-emitting apparatus extremely low in weight. However, the light transmitting tube may be covered with a transparent cover in order to hold and protect the light transmitting tube and prevent from leakage of light.
The light-emitting apparatus can be installed in a vehicle which is tall and has a running board at the underside of the entrance, such as a vehicle of off-road type, particularly in a manner where the light transmitting tube thereof is installed at the edge of the running board. In this case, the light transmitting tube installed in the running board can be extended so that the light source is arranged in a place which is far from the running board and in which the light source can be maintained easily.
The second object of the present invention is to provide a light device for a vehicle wherein the light device is low in weight and good in durability, and is easy to be formed in a curved shape corresponding to the shape of a car body which is formed in various curved shapes, and furthermore, the light device has a light source which can be repaired easily.
A lamp device for a vehicle of the present invention has a main body with a transparent part and a light-emitting apparatus installed at the back of the main body thereof. The light-emitting apparatus has a light transmitting tube which emits a light from its circumferential surface and a light source installed on one end of the light transmitting tube.
Light generated from the light source is introduced into the light transmitting tube and emitted from its circumferential surface, and the light passes through the transparent part of the main body of the lamp device and is emitted out.
The light transmitting tube may be arranged at the back of the transparent part without a cover, thereby making the lamp device extremely lightweight. However, the light transmitting tube is preferably arranged between the transparent part of the case and a reflective backing plate in order to hold and protect the light transmitting tube and prevent it from a leakage of light.
The light transmitting tube installed in the running board can be extended so that the light source is arranged in a place which is far from the running board and in which the light source can be maintained easily.
The third object of the present invention is to provide a meter case which is low in weight and excellent in durability and has a light source which can be repaired easily.
A meter case according to an aspect of the present invention has a main body having a transparent part, and an illuminating apparatus installed on the back of the main body. The illuminating apparatus has a light transmitting tube which emits light from its circumferential surface, and a light source installed at one end of the light transmitting tube.
Light from the light source is introduced into the light transmitting tube and emitted from its circumferential surface, so that the light is directed to the transparent part of the main body of the meter case.
A meter case according to another aspect of the present invention has a main body having a transparent part, a light-transfer board installed on the back of the main thereof, and an illuminating apparatus used for applying light to the end of the light-transfer board. The illuminating apparatus has a light transmitting tube and a light source disposed at one end of the light transmitting tube.
Light generated from the light source is introduced into the light transmitting tube and emitted from its circumferential surface, and the light enters into the light-transfer board through its end surface. The light emitted from the surface of the light-transfer board is directed to the transparent part of the main body of the meter case.
In each of these meter cases, the light transmitting tube can be extended so that the light source is positioned in a place which is far from the meter case and in which the light source can be maintained easily.
The light transmitting tube can be equipped with a tubular cladding and a core made of a material having higher refractive index than that of the tubular cladding. The light transmitting tube may be equipped with a belt-like reflective layer formed between the tubular cladding and the core along the longitudinal direction of the tubular cladding so that a light passing through the core is allowed to be reflected and scattered by the reflective layer and emitted from the side surface opposite to the reflective layer of the cladding.
In the light transmitting tube having the belt-like reflective layer formed between the tubular cladding and the core along the longitudinal direction of the tube, a strong light passing through the core (having the greatest capacity for transmitting light than the other portions in the light transmitting tube) is reflected by the belt-like reflective layer, and the strong light having a high directivity is emitted from a part of the outer surface area of the tube opposite to the reflective layer. As a result, the brightness of light emitted from the light transmitting tube is considerably high and thus the light transmitting tube emits a highly bright light.
The tubular cladding can be made of a (meth-)acrylic polymer, the core is made of a polystyrene, a polycarbonate, or a styrene-(meth-)acrylic copolymer, and the reflective layer is made of a (meth-)acrylic polymer containing a white color pigment or a light scattering material.
The light transmitting tube can be manufactured with high productivity and at low cost by the following method: a multiple color extrusion molding machine, for example, a three-material extrusion molding machine having three screw sections, is used; a material for the core (core material), a material for the cladding (cladding material), and a reflective material containing a white color pigment or a light scattering material are simultaneously introduced into each nozzle on the extrusion molding machine; in a simultaneous manner, the core material is extruded to be formed into a solid cylindrical core member, the reflective material is extruded into plural belt-like reflective layers formed on the outer surface of the solid cylindrical core member, the cladding material is extruded into a tubular member covering the solid cylindrical core member and the belt-like reflective layers, so that the belt-like reflective layers are formed between the tubular cladding and the core in the longitudinal direction thereof.
The light transmitting tube may be made only of a polymethyl (meth-)acrylate (PMMA), or may be equipped with a core made of PMMA and belt-like reflective layers formed on the outer surface of the core in the longitudinal direction thereof. The light transmitting tube may also be provided with grooves or concave holes which penetrate the reflective layer to reach the core. The core can be formed by extrusion molding method, injection molding method, cast molding method, and the like. It is preferred that the reflective layer includes TiO2, BaSO4, silica, and the like. The reflective layer can be formed by extrusion molding, coating, printing, and the like.
The core may have concave portions such as grooves and concave holes on the outer surface thereof instead of the reflective layers. The concave portions are preferably arranged in the longitudinal direction of the core.